Along with the development of the Internet, systems that enable the purchase of video content and the download of the contents from the content distribution servers to information processing apparatuses so as users can watch and/or listen to the content, are proposed. As a style of purchasing, one type is to buy video content and the other type is to rent content so as to be able to watch and/or listen to the content for a predetermined period of time. In the case of renting, the time period for watching and/or listening to the content is presumed to be limited. Therefore, the video content should be made unavailable for watching and/or listening to in the information processing apparatuses after the rental period has expired.    [patent document No. 1] U.S. Pat. No. 6,563,999